Press



Sept. 18, 1934. A. A. BYERLEIN 1,974,148

PRESS Filed March 10, 1934 Zhwentor Patented Sept. 18, 1934 1,974,148 PRESS Arthur A. Byerlein, Detroit, Mich., assignor to General Machinery Corporation, Hamilton, Ohio, a corporation of Delaware Application March 10, 1934, Serial No. 714,945

5 Claims.

This invention relates to presses and more particularly to the method of assembling the sections of large presses together.

One object of the invention resides in the method of assembling the-several sections of a drawing press or the like having assembly rods which hold the several sections together, in which the assembly rods are stretched under tension so the holding nuts can be readily tightened in order to hold the press sections together under initial compression with a force equal to or greater than the stretching force created during press operation. A

Another object is the provision of a press obtained by such method in which the press sections are each in direct contact with one another in superimposed relationship.

Other objects and advantages of the invention will be apparent from the following description, the appended claims, and the accompanying drawing, in which- Fig. 1 is a front elevation of a press showing how the assembly rods aie initially stretched or tensioned in accordance with the present invention;

Fig. 2 is a side elevation of the press; and

Fig. 3" is a detail view of the tensioning yoke.

Referring more particularly to the drawing by reference numerals, 10 designates generally a drawing or stamping pressadapted for working sheet metal or" the like, -As shown, this press comprises superposed sections, namely the arch 11, the opposite uprights 12 and 13 and the bed 14, each of which may be integrally cast or formed, these several sections being held rigidly together by means: of four vertical assembly rods, designated 16 and 17. These assembly rods extend through vertical holes provided in the several sections, and the upper and lower ends of the rods are provided with nuts 19 and 20 respectively in threaded engagement with the rod ends. The crankshaft 21 which drives the upper reciprocating slide or plunger 22 is rotatably mounted in bearings received in the upright and arch sections.

The nuts 20 may be tightened by means of wrenches or similar tools, but such tools are The nuts 20 are then readily tightened to mainnot suited to produce a desired initial tension or stress in the assembly rods, so it has been the" custom to stress or lengthen the assembly rods by heatingithem with a torch so as to cause their elongation, after which the nuts are tightened up and the rods permitted to cool. However, when this is done, most of the elongation of the rods takes place where they have been heated, and it has been found impossible to stretch the several rods uniformly throughout their length for this reason. There is a greater reduction in sectional area of the rods at the heated portions, and when the assembly is completed, there is no way of knowing if the tension on the rods equals the safe working capacity of the press. If the tension on the rods does not equal the safe working capacity of the press the rods will be stretched somewhat the first time the press is subjected to its full load, causing the frame to open at its joint and causing frame sway with resultant misalignment of the dies and shaft bearings.

In accordance with the present invention the assembly rods are uniformly stressed to the desired degree, when the rods are cold. This stressing or tensiom'ng of the rods is accomplished by applying a known force of the proper value to the rods, compressing the adjacent sections of the press and stretching the cold rods so the holding nuts 20 can readily be tightened with a bar or spanner wrench. The force applied to the rods at one end of the press is such as to hold the press sections together with a force stress equal to or greater than the stretching force created during press operations.

The initial tension in the rods is appliedby pulling the rod ends in the direction of their length by means of a fluid pressure jack 24 or the like. One end of each of the several rods 17 extends somewhat beyond the end press sec tion. As shown, the lower ends of the rods extend below the securing nuts 20, the threaded ends of the-rods being engaged by sleeves or posts 25 and 26 which are internally threaded at their upper ends so they may be readily screwed onto the rods. The lower ends of the posts are flanged outwardly, each pair of posts carrying a beam 27 which supports a jack 24. The upper movable element 28 of the jack bears against the bottom of the bed section. Oil or other fluid is then supplied under pressure to the jack or simultaneously to both jacks, to producefa known force compressing the press sections and stretching the rods tosuch an extent as to produce the initial tension desired.

tain the initial tension when the jack pressure is removed. It is then a simple matter to remove the jack and unscrew the posts 25 and 26 for the removal of the beams 27. The assembly rods 17 are thus uniformly tensioned in accordance with the requirements of the safe working capacity of the press, and stretched uniformly throughout their length while the press sections are securely held one directly against another under the desired initial compression.

While the method herein described, and the form of apparatus produced thereby constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. The-method of stressing the assembly rods of a sectional press comprising pulling endwise on the rods, while cold, with a force sufficient to cause the desired rod tension, and then tightening the nuts against the end section of the press.

2. The method of stressing the assembly rods 1 of'a sectional press comprising-compressing adjacent sections one against another and simultaneously tensioning the assembly rods, and then tightening the nuts against a press section so as to permanently maintain a desired initial elongation of the rods.

3. The method of stressing the assembly rods of -a sectional machine of the character described comprising jacking the ends of the rods through the end section of the machine so as to elongate and initially stress the rods under tension an amount at least as great as the force provided on the rods in normal machine operations, and then tightening the nuts on the ends of rods.

4. The method of stressing the assembly rods of a sectional press comprising exerting a predetermined compression force between the press bed and lower ends of the rods so as to compress adjacent sections of the press and initially tension the rods, and tightening the nuts on the rods.

5. A press comprising press sections each in direct contact with another in superimposed relationship, tension rods extending along said sections and holding said sections under compression, said rods having an initial measured tension at least as great as the force produced on v the rods in normal press operation and each rod being uniformly stretched throughout its length.

ARTHUR A .'BYERLEIN. 

